Nursing Elites

1. The energy required to break a chemical bond is called:

• A. Kinetic energy
• B. Potential energy
• C. Activation energy
• D. Bond energy

Correct answer: C

Rationale: Rationale: Activation energy is the energy required to break a chemical bond and initiate a chemical reaction. Kinetic energy (option A) is the energy of motion, potential energy (option B) is stored energy, and bond energy (option D) is the energy required to break a particular chemical bond in a molecule. Among the options provided, activation energy best describes the energy required to break a chemical bond.

2. Antibodies, crucial for immune defense, are produced by:

• A. Neutrophils
• B. Lymphocytes
• C. Monocytes
• D. Basophils

Correct answer: B

Rationale: The correct answer is B: Lymphocytes. Antibodies, also known as immunoglobulins, are produced by B lymphocytes (B cells) as a key component of the adaptive immune response. These specialized cells play a crucial role in recognizing and neutralizing pathogens, thereby providing immunity against infections. Neutrophils (A) are a type of white blood cell involved in innate immunity and phagocytosis. Monocytes (C) are another type of white blood cell that can differentiate into macrophages, which are important in phagocytosis and antigen presentation. Basophils (D) are involved in allergic responses and inflammation through the release of histamine. Lymphocytes, particularly B cells, are primarily responsible for antibody production in response to pathogens and foreign substances.

3. Which structure helps regulate body temperature by constricting or dilating in response to temperature changes?

• A. Sebaceous glands
• B. Hair follicles
• C. Sweat glands
• D. Langerhans cells

Correct answer: C

Rationale: The correct answer is C: Sweat glands. Sweat glands play a crucial role in regulating body temperature by producing sweat that evaporates from the skin surface, cooling the body when it's hot. Sweat glands can constrict to reduce sweating in cooler temperatures and dilate to increase sweating when the body needs to cool down. Sebaceous glands are responsible for producing oil to lubricate the skin and hair follicles help in hair growth. Langerhans cells are immune cells in the skin. Therefore, sweat glands are the structure specifically involved in regulating body temperature through constriction and dilation in response to temperature changes.

4. What is the unit of measurement for momentum?

• A. Newton-second (N·s)
• B. Kilogram-meter (kg·m)
• C. Joule (J)
• D. Meter per second (m/s)

Correct answer: A

Rationale: Momentum is defined as the product of an object's mass and its velocity. The unit of mass is kilograms (kg) and the unit of velocity is meters per second (m/s). Therefore, the unit of momentum is kilogram-meter per second (kg·m/s). By Newton's second law of motion (F = ma), force is measured in Newtons (N), which is equivalent to kg·m/s². Therefore, multiplying the unit of force (N) by the unit of time (s) gives the unit of momentum as Newton-second (N·s).

5. A water fountain has a spherical base (diameter 50cm) and a cylindrical body (diameter 30cm, height 80cm) on top. What is the total surface area of the fountain (excluding the water surface)?

• A. 3142 sq cm
• B. 4712 sq cm
• C. 5486 sq cm
• D. 7957 sq cm

Correct answer: C

Rationale: Calculate the surface area of the sphere and the cylinder separately, then add them up.

6. What is the purpose of the spindle apparatus in cell division?

• A. To separate sister chromatids
• B. To move chromosomes to opposite poles of the cell
• C. To form a new nuclear envelope around each daughter cell
• D. To synthesize new DNA

Correct answer: B

Rationale: Rationale: The spindle apparatus is a structure composed of microtubules that plays a crucial role in cell division (mitosis and meiosis). Its main purpose is to ensure the proper separation and distribution of chromosomes to opposite poles of the cell during cell division. This process is essential for the formation of two genetically identical daughter cells in mitosis or four haploid daughter cells in meiosis. Option A is incorrect because the separation of sister chromatids specifically refers to the role of the kinetochore fibers within the spindle apparatus. Option C is incorrect because the formation of a new nuclear envelope occurs after the chromosomes have been properly segregated. Option D is incorrect because DNA synthesis does not occur within the spindle apparatus; it takes place during the S phase of the cell cycle.

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